# python中实际上无常量且常量可被改变
Max_speed = 123
print(Max_speed)
Max_speed = 2000
print(Max_speed)

# 链式赋值
x = y = 123
print(x)
print(y)

# python赋值逗号表达式
a,b,c=1,2,3
print(a,b,c)

#系列解包赋值
a, b = 1, 2
a, b = b, a   # 在python中变量交换赋值很简单
print(a, b)


m,n,z=100,200,303
m,n,z=n,z,m
print(m,n,z)

